Visiting Wellington. Need suggestion about place to stay, things to bring etc.

Dear Friends,

My name is Alamu Am from Melbourne Australia. I am planning a short visit to New Zealand with my husband on 2nd week of January for my visa and need to stay there for a week minimum or atleast for 4 days depending on the situation. My work is in Australian High Commission Hobson Street, Thorndon, Wellington. Can anyone tell me how far is this place from Airport ? Is this place in city ? How expensive are the hotels to stay ? Do u suggest me to stay in a hotel Near to the Airport or near to the Australian High Commission? How is the climate during January? Is it going to be very Cold or hot ? What kind of clothing should I take for my travel.

Awaiting for a helpful reply
Thanks in Advance
Alamu